Polystyrene 50mm-is the most popular thickness, and the size of 1x1 m immediately give an idea of the cost per square meter. Why 50mm? The fact that many building structures are multiples of 5 cm Metal profile 50mm, 50mm bar, 100mm rack, Rafters 150-200mm and so on. For this reason, 50 mm polystyrene or a set of this thickness is most applicable.Builders-discount on the volume of the order.